By Wally Pyrah FORMER 12-time champion trainer John Size sets a conundrum for his followers at Sha Tin when saddling two of his potential superstars, Wunderbar in the Tailorbird Handicap (10.25am) over six furlongs and hugely talented Young Champion in the Woodpecker Handicap (11.00am) over six furlongs. Size’s stable is renowned for always starting a new season slowly, and you can probably count on one hand the number of times he has welcomed a winner in September. However, he will surely be expecting his smart gallopers to produce encouraging performances, notably Wunderbar, who returns to t…